text:
Do pilots really wear "pilot's watches"?
High-end mechanical wristwatches from Swiss and German manufacturers (e.g. Breitling, Rolex etc.) are often marketed as "pilot's watches", and have chronometer features to supposedly help pilots perform flight-related computations.
While I know next to nothing about aviation, I find it difficult to imagine that such a mechanical watch (which, for example, simply stops working if it is not moved for a few days) would be preferable to a modern quartz and/or digital watch, which keeps running for years on a single battery, self-adjusts with millisecond precision based on radio signals and even without that signal maintains time an order of magnitude more accurately than any mechanical watch.
To summarize: What kind of watches do modern commercial pilots actually wear? Or do they nowadays just use their cellphones for timekeeping tasks like everyone else?

May be they use apple watch

In the past, pilot's watches had a superior precision. Their display is easy readable, even at night, the big buttons can be pressed with gloves they had a stop watch,  a tachymeter and so on. They were (and still are) a piece of high tech. This and the myth around being a pilot makes this clocks very favored. Even in the past, only a fraction was actually sold to real pilots. I guess today some pilots wear them as they are made for them, not because they need them. This may be different for military pilots.

Totally off topic but divers do wear diver's watches, including Rolex Oysters. If your digital diving computer bonks, it's important to have a good backup so that you can time your decompression. And when your brain is bonkers on nitrogen poisoning, an analogue watch with one-way bezel is great. I personally use a Seiko Divemaster.

In my day, if you wanted to know what time it was, you asked the flight engineer. I couldn't resist that. Actually, though, there's more truth than not in that. On long-haul 747 flights with old steam gauges, the f.e. was the one keeping track of the fuel burn. His time, whether from a wristwatch or the clock on his panel, was the defacto cockpit standard.

It depends on the diver.  The former lead diver of the WKPP, arguably some of most hardcore extreme divers on the planet, wore and dove a very inexpensive Timex Ironman Triathlon digital.  (I picked up the habit from him, and dove one myself, with very satisfactory results.  It Just Worked.)  The key to dealing with nitrogen narcosis is not to have that much nitrogen in your mix in the first place.  (The first time I dove nitrox (EAN36), I discovered that I could tell the difference in 20 feet of water.  I never dove air again.)

Best reason I heard from a senior pilot - it gives him something to play with when his wife made him go to the opera.

On a watch manufacturer's point of view, it doesn't matter whether actual pilots are wearing watches or not. What matters is normal people still believing it. Just wisely use celebrity X, or important program/event Y to advertize your gadget Z, and that translates into $$$.

High end mechanical pilots watches are very little use in the cockpit whether you are in a commercial airplane or a cessna 152. I love watches and I've searched for years for a watch that was a) very cool looking and b) actually useful when flying and I haven't found one yet. They usually fail on b) because their analogue chronometer and/or timer functions are very hard to interpret, and cannot be read at night. The digital readouts on the analogue/digital types are often small and rarely have lights for night flying. Some have lights that will only work when in calendar mode, which is about as useful as a chocolate teapot. Often the functions are hard to use and require a fair amount of fiddling to get them to work, which is not good when you have a high workload.
Commercial airplanes are usually so full of technology that a watch is completely redundant anyway, so for commercial pilots it's a matter of style. I'm not a commercial pilot, I fly older light aircraft with less technology, so having a watch with timer and chrono functions is handy. For this I wear a Casio G-Shock as it has a large and easily readable face, a light activated by its own button, simple to use, and very rugged. Digital kitchen timers also work very well.

I want a chocolate tea pot!

@DanielGriscom: http://www.bbc.com/news/uk-england-york-north-yorkshire-29126161

Just saw that. I guess that's a Britishism; I haven't heard it before in the States.

It is a britishism @DanielGriscom. It's one of my favorites I've picked up living in the UK the past few years.

I think the reason that there's not a better true pilot watch is that the market is too small. What you don't need is a watch, what you need is a wrist computer. I was thinking of writing an android app which would run on an old mobile phone you could strap onto your wrist. It's a lot of work though, and as my experience with my BB Density Altitude app showed it's hard to make a profit of these things.

Years ago, I took off in a C152 with an examiner to do my night rating flight test and discovered that the timer in the aircraft was broken (poor pre-flight, I know). Fortunately, I wear a Breitling Navitimer and I used it for doing my timed turns. It works very well for that and I even used it later for the same purpose during my IR checkride. I don't think it's the best option for real IFR operations, but it's absolutely fine in a pinch.

@GdD I suppose you could just make an Android Wear app. Android Wear watches are quite literally wrist computers. You could even make set it up to program your route in ahead of time on your phone and have it show you the heading of the next turn and count down to when you should begin it, etc. Google Maps already does that for driving (except that, by default, it counts down distance to next turn rather than time.)

"Chocolate teapot" is totally replacing my go to expression "as useful as a bag full of rubber hammers".

The biggest concern for me in designing a pilot watch app would be making it do too much. A few simple, easy to use functions would not be distracting and would be better for head-up behavior. High technology can be distracting.

I am buying a Casio G-Shock right away, i knew since childhood, that it is the most versatile watch ever made, fit for all professions.

@reirab Garmin already makes several pilot watches. I can’t imagine it being very useful, but someone must have thought so. http://www.mypilotstore.com/MyPilotStore/sep/10546

@JScarry, I don't think the garmin watches were out when this question was asked, which was Sept 2015

FWIW, in the going on 40 years that I've held a (private) pilot's licence, I've never worn a watch.

I have a pilot watch (citizen promaster) and the only feature I routinely use (not being a fan on electronics navigational aids) is the calculator ruler, it comes very handy to do glide ratio calculations on, well, gliders.

Disclosure: I am both a watch enthusiast and a Pilot but on any note...
The answer to your question is generally no, but that varies by personal taste as well as personal choice. There are lots of threads on the various watch forums discussing this very topic here, here and here. The consensus is basically a few things. First off pilots no longer make the kind of money the once did and swiss watches have only shot up in price since say the 70's. If you are talking about an entry level professional pilot making in the very low 5 figures the chances they are going out and buying a $5,000+ watch is low. Now lets talk function. When you are in the cockpit a watch can be useful (provided you can read it). If your heading indicator fails you can use a watch and your turn coordinator to time your turns which can save your life in the clouds. I generally start my chronograph (omega speedmaster) when I take off, this gives me not only en route time but markers of the half hour blocks when I need to switch my tanks (on a piper warrior). For what its worth there is a clock in the plane as well as a timer so I don't need a watch but I enjoy wearing one. When I fly dead reckoning I carry an all mechanical Heuer Stop watch to time my legs. Again these things are in the plane but I find the hand held stop watch easier to use. Some fancy aviation watches provide flight computers on the bezels like breitlings but there is no way you are reading that in the air unless its really smooth up there.

The consensus around the internet and from what I have seen is that commercial pilots generally wear digital stuff or nothing at all (most casio and the like). Military fighter pilots where GShock's or what ever is issued if any thing is even issued. Some pilots may wear Rolex-GMT's or the such but that seems to be those that either really like watches or were gifted it etc. However Pan Am had a long standing relationship with Rolex over the years. Pan Am pilots may have sported an albino GMT or a special Pan Am Daytona depending on the era. The GMT Master was even designed in partnership with Pan Am and issued to long haul pilots.
On a side note there is a group of pilots that ALWAYS wear fancy swiss watches. Since the early days of the space program Omega has been the watch maker of choice for NASA and the Speedmaster has been the watch of choice as seen here on Buzz Aldrin

Some even say that the Speedmaster was used to time the engine burn on apollo 13 which may have in turn saved their lives. It is also reported that Neil Armstrongs Speedmaster Broke on the apollo 11 mission. Here is a comprehensive list of where all the watches reside now. The watches were worn on a NATO style velcro band that was a double wrap size so it could fit over the suits for EVA. The Speedmaster is still worn in space to this day however modern space suits have a flap covering it, making it hard to see in photos. The official Speedmasters (moon watches) are certified for maned space flight and stamped as such.

I would also like to expand on your statement

...which, for example, simply stops working if it is not moved for a few days

They do not stop working, the spring winds down and they will stop ticking however as soon as they are picked up again (and the rotor is spun if its automatic) they will start ticking again. That being said if you wear the watch every day, un like a digital that may die, a mechanical watch will tick perpetually until a component physically breaks.
On a bit of a tangent, some watch makers did make flight instruments (clocks) for aircraft over the years this is where much of the inspiration for the watches comes from. Elgin made a clock that was used in a few WW2 fighters,

Heuer even had an IFR stop watch

I doubt that that the astronauts buy their watches, they most probably get them free as part of promotional consideration from Rolex et al.

The astronaut watches are issued to them by NASA and are exclusively Omega Speedmasters (of varying versions over the years) the Speedmaster is one of the few watches certified for space flight and EVA operations. The only issuance of Rolexes I know of is the British divers who were issued mill spec submariners.

Sorry, Omega, yes of course. Shows how much good those promotional considerations are in raising brand awareness. ;-)

It was far more than promotion. NASA had very stringent requirements for the watch which included reliable operation in a huge temperature range, water proof and wind up (perpetual rotors don't work in space). The Speedmaster is a far more capable watch than most people give it credit for. I will admit Omega has made the best of it from a marketing standpoint ;)

If I ever need some inspiration, I look at that picture of Buzz or the more well known one of him standing on the moon.

Watches in today's cockpits really aren't a tool the way they were in the past. We aren't using our wristwatch as a chronograph to manage dead reckoning the way that was required before such modern luxuries as Loran gasp.
Wristwatches are more about expressing your style. It is more about jewelry. With the exception of a 24 hour Zulu hand, and a 24 hour bezel to be able to quickly reference three timezones, they mainly just look nice.
I have met some pilots that actually use the E6B on their watch, but most just like how it looks.
Aviation does have a very identifiable look, which is mainly what pilots are attracted to. Everyone likes to purchase things that are related to their passion, and flying is no different. Flight watches often resemble instrumentation and bring that part of the pilot's life to their wrist wherever they go.
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In fact, the first wristwatch was invented just for pilots. One of the first wristwatches ever made was named "Santos" by Louis Cartier, which was made for a famous pilot at that time who complained about having to check his pocket watch while flying. (Source: http://theaviationist.com/2013/12/25/aviation-wrist-watches/)
So, the two things are incredibly closely identified with one another.

Watches are extremely important for a pilot, especially small aircraft that do not have sophisticated instrument clusters. Everything is time-based and generally it is much better to trust your own watch than one built into the instrument cluster (unless it is a high-precision, calibrated clock on a large aircraft). Also, if anything happens that disrupts the aircraft functions or your visibility of the instruments, a watch is critical. For example, a fire or power failure can make a panel clock unlighted or obscured. Also, you may not be in the cockpit/flight deck and need to know what time it is.
The key factors for a "pilot's watch" are:

illuminated/visible in darkness
large numerals, clear and highly readable
ability to manage multiple time zones easily
24-hour (military/zulu) display capability
day of the month indicator
rugged and water resistant, tough crystal, good quality construction

Currently I use a Torgoen T05101. It is a good watch, but uses phosphorescence. My next watch will use tritium illumination.
I have been known to use an egg timer in the cockpit.

"I have been known to use an egg timer in the cockpit." I'm assuming you weren't doing a lot of negative G maneuvers while using it.

@DJClayworth I use an electronic egg timer that has a powerful clip on the back, not a sand glass. I usually clip it onto a convenient surface. It has an alarm, so it beeps when the time runs out. Its great reminder for tank switchovers and stuff like that.

@TylerDurden -- that might also be integrable into your watch (I have a Casio that has countdown timer functions on it, among other things).

I currently work as a corporate pilot. I have flown with hundreds and now verging on thousands of pilots- I have 5000 hours tt and I can say that most guys fly with cheaper watches and if they choose an aviation specific watch, it's typically a Citizen. I don't think that they love them, but they are affordable and don't break. I have one and am thoroughly tired of it, but it just wont give me an excuse to buy anything else. Although I have kept my CFI current, and could show you how to use all the features of the E6B, that feature is a joke. It's way too small to practically use. Of all of those guys and a few gals that I have flown with, only 4 or 5 wear an expensive mechanical watch. I have known a couple who had GMT Rolex variants, only one that I recall with a Breitling and I have run into a few of the smaller boutique brands on a few wrists, here and there. I personally flew with a Torgoen for awhile. The only feature that I do really like to have, although yes, it's available elsewhere in the plane, is a very easy to read GMT/UTC sweep.

I have two Citizen brand pilot watches and a Garmin SmartWatch.
I got my first Citizen one to commemorate passing my first checkride.
My wife gave me the second one on our wedding day.
I sometimes wear one while flying, but they've never been useful.
They both have an "E6B" dial, which is occasionally useful when flight planning (on the ground).  They also do Timezones and ZULU time very well, which is nice when I arrive at a destination.  But again, not much good in the air.
There is a new generation of Flight Watches that is slowly becoming popular, topped by the Garmin D2 Titanium.  These are more smart-watches than the traditional "swiss-style" watches.  With a built in GPS, database of waypoints, moving map, and bluetooth that can sync with my iPad and on board systems, its basically a mini-glass display on your wrist.   Variations run from about \$400 to \$900, so they aren't cheap.   I have the Garmin D2 Bravo watch, and there is a D2 Charlie with even more features.  A "D2 Delta" variant is likely in the works. They are pretty incredible in their capabilities.
I plan my route on my iPad, sync it over to my watch, and turn on the watch GPS slightly before takeoff.  When flying a steam-cockpit, having GPS navigation, ground speed, altitude and a few other features on my wrist is extremely convenient.

I use the stopwatch for IFR training and holdings and the E6B for fuel range computation, speeds etc. Heck I even use this this to convert feet to inches on architectural elements heights, distances etc. Just by looking at them you get the opposite heading easily, either for navigation or knowing opposite runway numbers. What if you need to take 30 or 45 degrees from that heading so you intercept final?
Most pilots that know how use them, do.

I prefer analogue over digital for the at a glance interpretive readability. My Revue Thommen Airspeed chronograph quartz has been utilized for dead reckoning (it does splits) and overall flight timing for 10 years. Light, thin, tough and practical. The battery last 2 years and I have it serviced regularly. Wearing it on the inside of my left wrist incorporates it easily into my scan. If it had a GMT hand and tritrium lume I would consider it to be perfect.

Im a professional pilot, and i do wear mechanical swiss watches all the time, specially my IWC Big Pilot, Breitling Navitimer, Chronomat and the Zenith Pilot. A reliable watch is a need for any pilot (since flights are always schedule-based). But wear a expensive swiss watch is a matter of style and affordability. Since im from a family of pilots for generations, the pilot's watch is like a heritage to us. The watch is the pilot's jewel (since the pioneers like S.Dumont, Louie Blériot, until the famous pilots like John Travolta, the Red Bull Racer pilots, the astronauts...those distinguished pilots always wears a good watch). But since a jewel is just a matter of looks (and affordability) my coleagues pilots wear mostly citizens brand and other watches (beause the luxury swiss watches are too expensive). But they always wear some good (dependable) watch.

Among commercial pilots its not really common to see stuff like Breitlings etc. What they need is something accurate, maybe with multiple time zones and not too expensive. Most Casios, Seikos and Citizens have the attributes I mention above so you see a fair bit of them.
Most pilots I know like to go out and see a bit of the city they're in (have a meal etc) when they have a layover. Wearing an expensive watch in an unfamiliar city is not really a smart thing to do. Also at some airports you have to remove your watch when you go thru security.. that's just another opportunity to lose one. Staying in hotels is another issue, if you're going down to the pool you have to remember to put the watch in the safe..and remember to take it out again when you leave for your flight!

Many do, but not for a different reason: many (not all) pilots are very well paid but have limited possibilities (time constraints, limited vacation, location and so on) to spend the earned money. Hence the expensive watches, regardless of their merit to the actual piloting.

Pilots are very well paid? I've never heard that assertion!

@dotancohen Everything once happens for the first time:-) I heard this very assertion from a pilot explaining why doesn't want a pilot's watch.

I'd appreciate if the downvoter left a comment as to what's wrong with my answer. Thank you.

Most pilots are not very well paid and even if they were time constraints would not keep them from buying an expensive watch. I assure you, from experience it does not take very long to buy an expensive watch.

@Dave Well, the first part really depends on your locale and on what you consider well paid. In Europe, most pilots are well paid indeed. As to the second part, that is exactly what I mean.


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Does "cleared into the Bravo at 3500" mean I must wait until I hit 3500 before entering it?
Let's say I'm two miles away from entering the class B, heading straight for it at 1500 feet and climbing. Approach control gives me my clearance as "...cleared into the class Bravo at 3500 feet...". On one hand, they know my heading and altitude, so I assume that I should continue straight on, entering the Class B in my climb and level out at 3500 feet, which I have done often with no consequences. However, a very literal interpretation of the clearance would have me turn away and remain clear of the Class B until I had leveled at 3500, at which point I could turn back and enter it. If push ever came to shove, which interpretation is correct?

Its non-standard phraseology and you should clarify with the controller. The controller should say something like "climb 3500 before entering Class Bravo", but either way if there is any doubt, you should ask for clarification with the controller. I'm assuming that this is VFR?

91.123: "When a pilot is uncertain of an ATC clearance, that pilot shall immediately request clarification from ATC". It seems unclear to me, so I would definitely ask the controller what he wants.

On one hand, they know my heading and altitude, so I assume that I should continue straight on, entering the Class B in my climb and level out at 3500 feet, which I have done often with no consequences.

This is what the controller wants you to do.  It's slightly sloppy phraseology - "Cleared into Bravo, climb and maintain 3500" would be better.  But what she said is not really ambiguous in any practical way.  She would definitely not be expecting you to turn away, then climb, then turn back toward the B.

That's going to depend on your circumstances and previous clearances.  Most likely it means you are cleared to enter a shelf of the class bravo airspace when your aircraft is at or above 3500' ASL.
Another interpretation is that you are cleared to enter a shelf of the class bravo with a floor at 3500', as listed on your charts.  Check them before proceeding.
Another possibility is that the instruction is part of a procedure for a VFR transit route through the Class Bravo airspace which required the pilot, after establishing two way radio communications, to enter the Class Bravo airspace at a particular point, at a specific altitude then follow an established course through the class bravo under approach control.  See the supplements for the Terminal Area Charts fro VFR through specific Class Bravo airspace.
But, yes the controller's instructions here are pretty vague.  I've never heard an approach controller say anything like that.

You could respond with "Cleared into the Bravo, climbing to 3,500, Nxxxxx" for your clearance read back to make your intentions clear.
For example, I was flying from west of Boston to the northeast, under the Bravo and skirting north of a Class D, and asked approach for flight following, with higher when able. Approach asked if I wanted clearance into the Bravo at 5,500, I said yes. Then he cleared into Bravo, climb to 5000 and direct to destination (being /G is nice for that).  Replied with 'cleared into Bravo, climb to 5,000, direct Pease (in this example), Nxxxxx'.  No problem.  I then continued to VFR at 5,500 after departing the Bravo and continuing northeast.

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What is meant by the term "Code on request"?
I recently flew from a small airport under a Bravo shelf into the nearby Bravo airspace above. When I advised the ground controller that I was doing as such, he cleared me to taxi, then added the frequencies for the Bravo approach control and said "code on request". A moment later he came back with a discrete squawk code. I'm assuming "code on request" meant he had requested a squawk code from approach control and was waiting for the reply, am I correct? Is any response required by me? I got my PPL at a smaller airport and had never heard that before.

I haven't heard this exact terminology before, but your interpretation sounds correct to me!

Instances of this expression can be found online, like here: After getting the ATIS, I call PAO ground and announce my intentions: "Palo Alto Ground, Cessna 96934 at Romeo 2-8 with Quebec for a Bay Tour." The usual response is taxi instruction and "code on request."

Yes, I think you're correct although the phrasing is unusual. The usual phrase is "clearance on request", which is used for IFR departures as explained nicely in this AOPA article:

Experienced instrument pilots know that when they call to request
  their clearance, the controller may not yet have received it.
  "Clearance on request" is ATC's way of politely saying "I don't have
  it - I've requested it - you'll be the first to know when I get it!"

The only FAA reference for the phrase that I could find is buried in the glossary of the Pilot's Handbook of Aeronautical Knowledge:

Clearance on request.  An IFR clearance not yet received  after filing a flight plan.

But as RalphJ commented, if this is a VFR scenario and you needed a class B clearance and transponder code then I assume that the controller said "code on request" to let you know that he was waiting for a transponder code for you, as you assumed.
It wasn't an instruction as such so you could just acknowledge it with "Roger" or whatever. See this question for more information on that.

He wasn't getting an IFR clearance, just a transponer code. Same concept, but a different thing the controller would get back from Approach to give to the pilot. The OP's understanding is correct.

I don't believe these are related - he's talking about a VFR departure, I believe.

@RalphJ That makes sense, the "code on request" phrase is nowhere to be found in any document, so I assume it's by analogy to "clearance on request". I'll update my answer.

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Is the "Bay Tour" flight path documented, or is it a more informal route? Are there similar flight paths for other cities?
During my Private Pilot's Licence days out in San Francisco, we often flew a "Bay Tour": a sightseeing flight northbound from San Jose through SFO's Class B , over the city and Golden Gate Bridge, then east to Oakland and south to return to SJC. Local approach controllers were familiar with this route, and a pilot could file a flight plan for a Bay Tour with everyone knowing what he was talking about. In addition, the tower at SFO would often go out of their way to give aircraft on a Bay Tour a better view of A380's and 787's out of SFO. However, I can't find any official information on it. Is it a published procedure, or just something that everyone out there has come to know about? Do similar flight plans exist for other cities and if so, where can I find information on them?

There certainly are similar routes - the Niagara Scenic Falls route, given in FAR 93.71 comes to mind.  (FAR 93 has plenty of these, by the way.)

Comply with the following procedures when conducting flight over the
  area described in paragraph (a) of this section:
(1) Fly a clockwise pattern;
(2) Do not proceed north of the Rainbow Bridge;
(3) Prior to joining the pattern, broadcast flight intentions on
  frequency 122.05 Mhz, giving altitude and position, and monitor the
  frequency while in the pattern;
(4) Use the Niagara Falls airport altimeter setting. Contact Niagara
  Falls Airport Traffic Control Tower to obtain the current altimeter
  setting, to facilitate the exchange of traffic
  advisories/restrictions, and to reduce the risk of midair collisions
  between aircraft operating in the vicinity of the Falls. If the
  Control Tower is closed, use the appropriate Automatic Terminal
  Information Service (ATIS) Frequency;
(5) Do not exceed 130 knots;
(6) Anticipate heavy congestion of VFR traffic at or above 3,500 feet
  MSL; and
(7) Use caution to avoid high-speed civil and military aircraft
  transiting the area to or from Niagara Falls Airport.

As a Bay Area pilot, I've wondered this too.  It appears to be an unofficial but widely-understood local custom, similar to the not-always-charted VFR reporting points commonly in use at many local airports.
Moreover, it seems there isn't just one "Bay Tour".  Instead, I think that phrase generally tells the controllers that you're on a sightseeing flight rather than simply trying to get from point A to point B.

There is not one official "Bay Tour" flight route. However, there are general guidelines to follow. This local flight instructor's site explains this and offers suggestions of where you can get a map. Here is a flight briefing for one possible route.
In general, there are VFR Flyway Planning Charts that you can use in certain areas of the country. San Francisco has one of these.

Flyway Planning Charts depict flight paths and altitudes recommended for use to by-pass areas heavily traversed by large turbine-powered aircraft. Ground references on these charts provide a guide for visual orientation. VFR Flyway Planning charts are designed for use in conjunction with TACs and are not to be used for navigation.

Example section of a VFR Flyway Chart:


text:
Can people who suffer from motion sickness become pilots?
Suppose a person suffers from motion sickness when flying, but wishes to become a pilot (let us say, with the eventual goal of flying for a major commercial airline).  Is this possible?

Is motion sickness a medical disqualification for a pilot's license, in many or most jurisdictions?
Most over-the-counter motion sickness medications cause drowsiness, so they are obviously not a good idea for a pilot to take.  Do pilots have access to other effective treatments that are safe to use while operating an aircraft?
Do pilots find that they get over motion sickness the more they fly, similar to the way sailors develop "sea legs"?
Are pilots taught techniques to remain focused on flying even if they are experiencing motion sickness symptoms (nausea, vomiting, dizziness, etc)?

I should read the question better, saw you mentioned sea legs :P What I also found is that being mentally occupied/stimulated also distracts from the nausea. If you need to fly the plane, I think the nausea will not be such a significant distraction.

In a car the driver does not experience motion sickness even if they usually do as passengers. However in a car one can anticipate most motions from the control inputs and what they see, which is not the case of aircraft in turbulence. In a car one also always has visual reference, which again is not true of aircraft in instrument meteorological conditions. Therefore I am not sure how much the effect applies to aircraft.

@JanHudec: Also, for aircraft with two pilots, the "control inputs" point would not be much help for the PNF.  There would be a similar issue for a plane with an autopilot.

Visual cues do help ppl with motion sickness. I am slighly prone to motion sickness in the back seat of a car, but not the front passenger seat or while driving. If I try to read or something where im not loking out the window I can get a little queasy too. For me it's the lack of correlation between visual cues and vestibular cues. But there's a difference with flying. You can see bumps and curves, but you can't see turbulence. Sometimes you can't see anything. Oddly, though, I never get sick riding on an airplane - go figure.

I have motion sickness (can't read while in a car even), but flying is fine except for unusual attitude practice.  That makes me sick, so we always just do that last.  Oddly flying IFR through bumpy clouds is fine.  It's just the specific procedures for unusual attitudes that make it unbearable.

The short answer is yes. I can't answer all your questions in detail, but here's some US-based information.
First, is it disqualifying? According to the FAA, if a candidate for a medical says he suffers from motion sickness then "a careful history" is required, and if the person requires medication then FAA approval (i.e. a special issuance) is needed. So it all depends on the person's individual situation, but it is definitely possible to get a medical, even if you require medication. Motion sickness also seems to be fairly common in new pilots, by the way:

Approximately 10% of all students taking flight training will become
  airsick at some point during their first 10 flights; 15-20% of these
  will have a severe enough form to interfere with their control of the
  aircraft.

Second, are there alternatives to medication? The FAA has a video about motion sickness and how to deal with. I haven't watched it but the description implies yes:

This video provides practical advice on diet, medications and other
  exercises to help cope with this potential problem

Wikipedia also mentions various treatments although some (like head-mounted displays) seem impractical for civil aviation at least.
Third, do pilots adjust over time? Apparently, yes. This FAA document says:

The experienced or acrobatic pilot is conditioned to withstand abrupt
  attitude changes that a passenger or helicopter pilot might not have
  experienced.
[...]
Continued gradually escalating exposure is the most common process for
  facilitating adaptation. Several days and repeated sessions of flying
  usually conditions the patient to the new environment.

That exposure would also be an alternative to medication, of course. And Sami's answer has some interesting personal experiences.
Finally, are pilots taught techniques to stay focused on flying? Instrument rated pilots are trained to ignore their physical sensations and focus fully on their instruments instead. But that training has nothing to do with motion sickness as such, and I have no idea how pilots who do suffer from motion sickness are affected (or not) when flying on instruments.

I would like to add a youtube video which was recorded by a fighter pilot. He is saying that fighter pilots also experience motion sickness, but with training people can get over it. Please see the link https://youtu.be/3TkPxtuqyn8

I think there is no straight yes or no answer to this question. It all depends on the level of one's sickness.
"To suffer from motion sickness" is a relatively loose definition. I would say everyone suffers from it, once the motion is rough enough. The key is how much can one take and how much it affects one's ability to pilot the aircraft. A pilot shouldn't get sick in normal operation.
Out of personal experience, I suffered from motion sickness during my initial training in air force. I got nausious on aerobatic flights, and that prevented me from going beyond basic training. However, I applied to a civil aviation academy and I'm currently employed as a commercial airline pilot, and have no problems with motion sickness in an airliner.
A commercial jet pilot doesn't experience aerobatics or rough maneuvres and therefore is less prone to nausea.
As of the sea legs, yes. Experience most certainly helps, and one gets less and less nausious.
Simplified a little, motion sickness itself is caused by conflicting perceptions from your balance organs (sorry, don't know all the english terms) in your middle ear and from your secondary balance receptors, such as sight.
Meaning that if your inner ear organs feel that you're for example tilting your head to the right, but if you read a book and the book stays still, your sight is telling you that you're still. Your brain can't decide which one is correct, and you get nausious.
During pilot training this is explained, but at least in my studies, the techniques to handle motion sickness was mostly up to me.

Can you share your motion sickness handling technique with us?
Anyway, I found this source which may be helpful in combating motion sickness:
https://www.aopa.org/go-fly/medical-resources/health-conditions/ear-nose-throat-and-equilibrium/motion-sickness

With regular practice, your body may become used to the motion so that motion sickness lessens or goes away (also going on roller coasters etc may help - although I personally don't like roller coasters and have never tried it).
You may find that being in the driving seat (i.e. doing the flying), lessens or removes motion sickness and you only feel it as a passenger when you are not looking at an horizon (real or artificial). I can go up in the roughest weather when I'm doing the flying but don't like it too much when a passenger.
But if these (and other measures) don't work, ultimately it may well stop you if you have symptoms anything other than very minor, because motion sickness is so debilitating, it would prevent you from relaxing and stop you from thinking and functioning as a pilot.

Also you might find this article interesting http://aviation.stackexchange.com/questions/8484/what-can-i-do-on-the-ground-in-order-to-help-my-body-acclimate-to-aerobatics?rq=1


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How does ATC handle changing QNH/altimeter values?
Obviously for aircraft arriving to or departing from an airport/airspace (as relevant), they listen to the ATIS and/or are given the QNH.
But what happens if that pressure changes? Even a fairly small change can make a big difference when we're dealing with 1000ft of vertical separation (which can be much less by the time we account for human margins for error).
Is the new QNH announced to the entire frequency, or similarly the change of ATIS, which each aircraft would then be expected to check? Or would it just be updated when assigning a new altitude to any aircraft already in the airspace?

Bear in mind that in terms of separation between aircraft, the actual QNH doesn't matter so long as everyone is using the same value.

@dan that's my point - I'm asking how everyone is updated when the value changes to avoid people using different values and therefore being closer than they expected

In the US, ATC simply broadcasts a notification on whatever frequency is needed. For the terminal environment, section 2-9-2 of the ATC orders says:

Broadcast on all appropriate frequencies to advise aircraft of a
  change in the ATIS code/message.

The phraseology is usually something like this:

Attention all aircraft, Bowman information Kilo is now current.

For en route operations (see section 2-7-2) the ARTCC gives altimeter setting updates directly:

Attention all aircraft, the Nashville altimeter now 2992

Similar to UK although the broadcast call sign is "All stations".

PLEASE NOTE: This answer is only correct for FAA rules! In all other countries which work according to ICAO rules a broadcast of QNH changed is PROHIBITED! So eg. in european airspace we have to address every aircraft to provide the revised QNH‘

@pcfreakxx That seems excessive. What about if it's a change in ATIS? Does that have to be given individually?

@DJClayworth I don’t get exactly what you mean, but if the ATIS changes we will tell the aircraft to „check info G“ or whatever letter it might be

@pcfreakxx I mean do you have to tell each aircraft individually that "Information Golf" is now current?

@DJClayworth Yes of course! Or, in case of minor changes, we will advise the change straightaway instead of a revised ATIS

The simple answer is, usually the altimeter setting does not change fast enough for it to be an issue.
Near ground level, one-hundredth of an inch of mercury (00.01 inHg) corresponds to roughly ten feet of pressure altitude. Thus one inch of mercury corresponds to one thousand feet of altitude. (This rough rule of thumb can be seen by looking at a lowest-usable-flight-level table: Below 2992 FL180 is unusable, below 2892 FL190 unusable, below 2792 FL200 unusable.) This is close to negligible for separation purposes, given that minimum IFR-IFR vertical separation is 1000 feet and ATC scopes only display altitude to the nearest 100 feet. Of course arrival aircraft are more concerned with having the latest altimeter setting, especially if the ceilings are close to instrument approach minimums!
If the atmospheric pressure is changing quickly, the weather station will note that with the remark PRESRR (rising rapidly) or PRESFR (falling rapidly). This provides a heads-up to pilots and ATC to keep an eye on the setting. What is "rapidly"? 00.06 inHg (sixty feet) per hour! Not a gigantic difference. It's not super rare to see this at my facility but it's not an everyday occurrence by any means.
When aircraft are enroute below the flight levels a controller should advise them of the nearby altimeter setting "at least one time when operating within [their] area of jurisdiction" (7110.65 2–7–2 c1). Essentially every time an aircraft is switched to a new facility they will get the local altimeter setting, and by listening when new arrivals come onto the frequency they can update as needed. If an aircraft is showing drastically off (300+ feet) from their assigned altitude, ATC will re-issue them the altimeter and ask them to confirm their indicated altitude.

Where ICAO rules apply (e.g. most of the world), broadcasting a change in QNH to the entire frequency is not sufficient. The QNH is considered (for good reason) to be safety critical information, and so each aircrew most positively acknowledge that they have correctly received it. This means informing each aircraft on the frequency of the new QNH, and wait for them to read back.
I'm sure this is not always actually done, but it is what the rules say.
Reference: ICAO document 9432, 2.8.3.5:

The following information shall always be read back:
[...]
c) runway-in-use, altimeter settings, SSR codes, level instructions, heading and speed instructions and,
whether issued by the controller or contained in ATIS broadcasts, transition levels.

Do you have a reference for the need to inform each aircraft individually?

I may be wrong, but it looks to me like section 2.8.3 is specifically about clearances? It makes sense to require a full readback after issuing a clearance to an individual aircraft, but that seems like a different scenario from informing all aircraft on frequency about an altimeter change.

@Pondlife You do have a point. Document 4444 and Annex 11 contain similar paragraphs requiring readback of altimeter settings, but those are also contained in sections specific to ATC clearances. The requirement to read back QNH is one thing though, another point is do controllers have to inform of a change in QNH at all? The obvious answer is yes, but I can't seem to find and source for this in ICAO documents.

From document 4444: "7.4.1.2.1    Prior to taxiing for take-off, aircraft shall be advised of the following elements of information, in the
order listed, with the exception of such elements which it is known the aircraft has already received: [...] c) the QNH altimeter setting and, either on a regular basis in accordance with local arrangements or if so requested by the aircraft, the QFE altimeter setting;" - this suggests that crews should recieve regular updates of QFE settings, but not necessarily QNH.


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61.113 - is paying your pro rata share limited to the time you are in the plane?
Is the pro rata share that a passenger pays limited to the time he spends in the plane, or can it apply to the whole “operation”?
Let’s say my friend, who lives 100 miles away, asks me to fly him on a tour of his hometown. I take off from my home airport, fly 2 hours to his local airport, and land to pick him up. After flying him on a 1 hour tour, I drop him off and return, solo, to my home airport. Upon landing, 2 hours later, I refuel and, finding that I spent 100 dollars on gas for the entire day, prompt him to pay me 50 bucks. Given I made all legs of the flight for the sole purpose of entertaining his desire. Is my request for 50 dollars legal? Or, given that he was only in the plane for 1 hour out of 5, am I only entitled to 20?

This is a violation of the FARs, but this kind of thing happens all the time. The FAA neither notices nor cares about it unless there is some other reason for them to get involved in the flight.

"asks me to fly him on a tour of his hometown" - you are breaking the law. You wouldn't have made the flight without being asked.

@Steve Kyoto, BS.  Quote me the CFR that describes who is allowed to come up with the idea of going flying.  Now I agree that this particular case is on or past the edge due to the multiple legs, but friends go flying all the time.  Nothing says it always has to be the pilot’s idea.

The situation you're describing is a commercial operation. Without a commercial certificate (and a part 135 operation) you may not receive any compensation at all.
The FAA has consistently held that the 61.113's non-compensation exemption in 61.113(c) requires common purpose for the pilot and passengers (Bobertz - 2009, p.2):

Absent a bona fide common purpose for their travel, reimbursement for the pro rata share of operating expenses constitutes compensation and the flights would be considered a commercial operation for which a part 119 certificate is required.

There is unfortunately not a strict definition of common purpose. However, the basic ground rule is that to fall under 61.113(c), the pilot must have their own reason for making the flight, independent of the passenger's.
The Bobertz interpretation presents an illustrative example: if a pilot wanted to go to a race, they could bring contestants to the race as passengers, and receive compensation. Because the pilot was flying there for the purpose of attending the race, common purpose is established, and pro-rata cost sharing is permitted.
However, if not all of the members of the race team could fit in the plane, the pilot could not share the cost to go back to the origin to make a second trip: there's no independent reason to do so. This crosses the line into a commercial operation, so no compensation is allowed.
Applying these guidelines to your question, the key phrase here is:

I made all legs of the flight for the sole purpose of entertaining his desire.

There is clearly no common purpose. Therefore, accepting any compensation for the flight, even a pro-rata cost, is compensation in violation of 61.113.

There's a grey area here for sure but in practice I don't think the FAA would have any interest in this scenario. They just don't care about a pilot taking a friend for a flight - it happens every day - and private pilots have to be able to use their privileges otherwise what's the point? If the friend offers to pay all the costs, or asks the pilot to take him somewhere on business, or to fly him somewhere every week, that's clearly commercial.

@Pondlife There isn't a grey area at all. The FAA has consistently held this position since at least 1985. Whether they would consider this situation not big enough to enforce is unknown, but the rules themselves are 100% clear - and the question was "is this legal", not "could I get away with this".

Agree...this is pretty clear cut.  Chris is probably a commercial op in this scenario.  He could be dinged even without any money changing hands.

Fair enough, I re-read Bobertz and it does indeed seem like a very similar scenario to this one so I've deleted my answer.


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Identify this high wing aircraft with engine side-pods
Was watching this video from 1967 and saw an interesting high-wing plane that looks to be about the size of a Cessna 206, but with what looks like a really unique dual engine side-pod configuration. I was unable to figure out what the make/model is if anyone is familiar.

It looks like a Stinson Model U Airliner, but seems too small.

I'm pretty sure it's a Dornier Do 28 A1. The aircraft first flew in 1959, and was followed by the similar but larger Do28 C in 1966. You'll find more on Wikipedia

Source: Wikipedia Commons

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Why is the cirrus yaw damper disabled during takeoff?
I flew an SR22T the other day, the first high-performance airplane I've flown and I was incredibly surprised by the amount of yaw induced during a touch-and-go, nearly causing a ground loop.
After the flight I went and read about the yaw damper feature on the aircraft and learned that it doesn't engage until 200ft AGL. Why is the damper not available for use at takeoff considering the large torque-induced yaw produced in aircraft like this?

A yaw damper on a single suggests the plane is "under-finned" so the yaw static stability is only mildly positive. The result is stronger torque reactions and an annoying tail wagging tendency in bumpy air. Rather than enlarge the fin, which would mean revising the entire fuselage mold, easier to add a YD. The other benefit is you don't have to use your feet at all while hand flying the thing, which is also the case with jets.

@JohnK Interesting, I guess it's entirely possible considering how they've been upping the HP on these things without airframe changes. Considering the target market, I would definitely also assume that relieving the pilot of turn coordination (among other things) is a big selling point.

As pointed out in this answer, the term yaw damper is a bit wide. This autopilot function is typically used to

Dampen unwanted oscillations in the yaw axis such as the dutch roll mode
Helps to keep coordinated turns by counteracting sideslip
Can be part of an Automatic Flight Control System (AFCS)

This is also described in the according manual (page 414).
However the seconds point becomes important for the take-off or landing of a small general aviation aircraft such as the Cirrus: In a cross-wind landing, the pilot tries to achieve a sideslip angle, to be able to land on the runway. The yaw damper would try to counter-act this sideslip. For this reason it has to be deactivated for the landing. The same holds true for take-offs: In order to be able to fully control the aircraft e.g. in a crosswind, without having unwanted inputs by the yaw damper, this system is fully deactivated.
In pretty much all other flight states (e.g. 200 ft above ground), you most likely would never fly with a sideslip angle.
According to the flying magazine, a second reason (although only for bigger aicrafts) can be:

Attempting a takeoff in a large aircraft with the yaw damper engaged could lead to
the airplane correcting on its own for adverse yaw in the event of a
power-plant failure. That makes identification of the failed power
plant more difficult

@Jamiec you are right, I reformulated my answer to make it a bit more sound and point this out.

I would disagree with FLYING's answer. Airliner YD systems are always running in the background. When an engine fails on an airliner, the YD doesn't disengage itself. Its authority is so limited, about 1/4 of rudder travel, it has little noticeable effect. With a swept wing jet, if you don't input a LOT of rudder right now when an engine quits at takeoff thrust, you will be on your back shortly. Whether YD is engaged for not matters little. In the case of the Cirrus, resistance to cross control inputs when you really need them is probably the best reason.

@JohnK Good point on the pilot authority to input cross-control, in-fact that may have been what allowed me to keep the wing off the ground. Had it input right rudder at that point, things probably would have ended up much worse.

@U_flow I appreciate the answer! These are all great points, but I'm most interested in the takeoff as that's where torque and p-factor induced yaw is the biggest problem if you have any other info on that phase (maybe we should roll-up John's point about the importance of pilot authority).

@joshperry when the Cirrus's YD is engaged, do you feel the rudder pedals moving under your feet? On airliners with cable/hydraulic controls, the YD is often just a servo in the linkage ahead of the rudder that lengthens and shortens the linkage, and you don't  have any movement of the pedals.

@JohnK Unsure, after the first T&G we were all a bit shaken and just brought her back to the ramp. I was not really conciously pushing the rudder pedals at all, it had been awhile since I had flown even the 172 which is at least partially why I transposed to turning the stick in a panic instead. Because of that my right wing was really low while the plane was torquing to the left, adding right yaw at the wrong time there seems like it  could have contributed to stalling the right wing (or at least adding lift to the left and exacerbating the roll).

@joshperry Well, about the cross-control inputs: This is certainly a point. However, we just do not know which exact argument lead to the design decision to disable the yaw damper below 200ft, for this reason I want to keep my argument as general as possible. I extended the argument of the answer to take-offs as well and inserted the Garmin flight manual for the avionics.

Thanks @U_flow!


text:
Could an airliner (in theory) fly truly "backwards"?
Very much a hypothetical question:
At Trondheim a few days ago we had quite a long, fast (to my experience) pushback: now obviously we didn't hit anything close to Vr, but it started me wondering if an airliner could theoretically fly in reverse.
Say for the sake of argument that we flipped the engines round without introducing any other problems, and stuck a window in the tail with a seat, controls and flight instruments in front of it... then put the plane on a runway and tried to take off. Would the airfoil allow the aircraft to take off? Would it be in any way controllable? Obviously I'm not expecting the plane to be flyable by a pilot, merely curious if it's theoretically possible aerodynamically (perhaps computer controlled).

Related: http://aviation.stackexchange.com/questions/19114/can-a-plane-fly-backward-if-its-propeller-is-in-reverse?rq=1

It would be kind of like throwing a dart feathers first.

Maybe you want to ask first if a wing could generate lift backwards (that is with an angle of attack near 180°), because for an aircraft you are also adding the problem of converting the tail surfaces into canards, which is a big issue.

@mins - basically, yes - I asked mostly under the assumption that the control surfaces wouldn't actually be usable, but that would perhaps have been a clearer question

Look at the lift/drag ratio for this airfoil, just after 180° (which should be the actual AoA for the wing in your question). It seems the airfoil has some lift.


text:
What happens when a pilot has no Instrument Rating and visibility drops?
Note: I'm not a pilot, so I don't have much basic knowledge of how the pilot licence ratings work
If a pilot doesn't have an Instrument Rating, and the weather conditions drop below VMC; what do they do?
Presumably you can't instantly land, but nor can you safely continue to fly without sufficient visibility?
I know the basic licence includes some instrument training, but is this enough to fly and land without visibility? I was under the impression that was the entire point of gaining an Instrument Rating... To train the pilot to fly on instruments alone

Obligatory: http://www.aopa.org/AOPA-Live.aspx?watch={CCA30EA1-A94D-4E45-ABCD-3AD4074403E0}

@falstro: interesting. Why is it so lethal? (I'm not a pilot).

@AE You lose the actual horizon which most VFR pilots use and if you are not trained to keep an eye on the artificial one you won't notice an odd attitude until you are nose down in the ground.

@ratchetfreak - thanks for info - but presumably VFR pilots all know this and yet the same thing still happens to them? Is the artificial horizon just unusable unless you're specially trained for it? As a lay person it looks pretty easy to understand.

@AE it's not so much the horizon, it's the visual cues that are gone, nothing moves any more, or moves in directions inconsistent with the actual movement of the plane. Add that to sensations of movements by our inner ear and other sensory systems, and we're all pretty much doomed without training. Classic test, close your eyes and let someone spin the chair you're sitting in. Eventually you'll get the feeling you've stopped (fluid in your ear has caught up with the rotation). Open your eyes and you'll go dizzy due to the fact that your eyes are now telling you you're still actually spinning.

That's a very good point - surely anyone in a plane understands the basics of the artificial horizon and airspeed? Call me over-confident, but I'm pretty sure I could keep an already airborne and stable aircraft in the sky as long as those two were working - at least until I ran out of fuel.

@JonStory ok. Mr. Over-Confident. :) Yes, you probably could, but as soon as you take one look away from that instrument, switch radio frequency, change VOR radial, GPS configuration... There's more to flying a plane than keeping it stable. Especially if you're in the soup, and you don't want to be there anymore. You look back at that thing and it'll now show a weird angle, your AI just failed. Only, as the post crash analysis might show, it didn't, it just didn't tell you what your stressed out mind was able to accept.

I'd probably assume the instrument hadn't failed and fly to correct it, to be honest - if the instrument fails I'm dead anyway, with no other point of reference, so I doubt I'd waste time second guessing if it's working or not. Perhaps I'm unusually logical though

You have to consider the situation you're in too. How did you end up in IMC? If you for funsies flew into a puffy cloud only to come out the other end, you'd probably manage (but don't, it's stupid). A better bet is that you're trying to beat a low ceiling with a good deal of haze that you can't tell the clouds from neither the sky nor the ground. Where are you when you suddenly lose sight of everything? 1000' off the ground? 500? Where's that radio tower or huge wind turbine you see in your chart? You will have a lot on your mind; and most likely, as the video says, 178 seconds to live.

You're not unusually logical; but you've also never been in that situation. Most people think they'll do just fine. Keep in mind, every fiber of your body is telling you you're sitting upright, only that instrument isn't. I have been in that situation, and it wasn't even in IMC. I was looking at my chart for too long. The feeling when you realize it's not what your body tells you is extremely humbling.

Fair point about altitude - I can see how even an experienced pilot would be in trouble when not sure of bearing and having to quickly find airspeed, altitude and attitude while working out what he needs to avoid

@JonStory The leans are quite common even in VMC when you can see the horizon, so you can imagine how much more difficult it can be in real IMC. This is also worth a read.

@JonStory looking at one instrument on its own is easy.  Looking at 6 instruments at once is a bit more work.  Crosschecking that they all agree to identify a failed instrument is yet more work.  Ignoring the kinematic sensations your brain tells you that conflict with what the instruments are telling you is probably the hardest part.  Doing all of this while remembering to fly is more work.  Doing all of this while navigating is still more work.  Doing all of this while talking to ATC, more work.  Doing all of this while briefing and flying an approach, lots of work.  Hope you brought charts.

@falstro Regarding thinking the AI is wrong, couldn't you figure out that it's accurate pretty quickly by cross-referencing it with the VSI, HI, and airspeed indicators? That is, if it's showing you're banking and you don't think you're banking, it seems like a quick look at your HI and compass would confirm which is accurate. Similarly, VSI, altimeter, and ASI could confirm if you're climbing or descending.

@reirab Yes, you can. And indeed that's what you'll do after several hours of IFR training, and you've picked up an instrument rating. But until you get proper training and have experienced the tricks our minds play first hand, you will not be able to fight the urge to trust your senses.

@falstro Interesting. It was the first thing that came to mind for me while sitting here at my computer, but I can see how it might not be when I'm busy trying to fly an airplane. Thankfully, I've not flown into IMC, so I can't speak for what that feels like. I check the weather before flying and simply don't fly if the weather is going to be nasty.

@reirab have you ever flown with a stuck attitude gyro? Figuring out its failed is the easy part. Now try to remove your main attitude gyro from your scan. You've got the leans, and you're trusting your instruments to stay alive, except that now your instruments are lying too. Its incredibly confusing and vertigo inducing and likely only survivable through a lot of repetition. Every time you forget and correct using your failed gyro you go further into confusion and have to rebuild your SA bubble. I've done it once in real life and, without prior training, I would have died.

@SHAF I haven't flown with one that was actually stuck, though I have flown with one whose readings weren't quite accurate... and an HI that likes to drift a little. Fortunately, I was flying in VMC, so it didn't really matter. My previous comment was directed at what to do to verify that the attitude indicator was not lying to you in IMC, not what to do if it actually is lying to you. Obviously, that's a whole different ballgame.

@reirab and the point still stands that even if you cross check and figure out the discrepancy, unless you've had prior training, it probably doesn't matter.

"Get out and walk"

@falstro Is that link still current? It looks pretty stock and bland compared to the URL.

@RhinoDriver: Why not carry a stickynote or suction cup with you for covering up failed instruments (like flight instructors do to simulate instrument failures when teaching partial-panel flight)?

It is very rare for weather to go IMC unexpectedly.
A responsible pilot should see that weather is deteriorating, and begin planning for the nearest available landing.   If they cannot find a landing, they should contact ATC while still in VMC, declare an emergency, and begin working with ATC to get down safely.
In some cases, a pilot may inadvertently enter IMC unexpectedly.   The standard procedure is to execute a standard rate 180° turn, and fly equal time in the opposite direction.  That should get them back to VMC conditions.
If that doesn't work, unfortunately inadvertent flight into IMC is a leading cause of GA accidents, especially CFIT (Controlled Flight into Terrain - i.e. 'aircraft flew into the ground').   Because of that, even basic private pilot training includes more basic instructions on instrument flying (BAI) than it used to.

Good answer - thanks. It did occur to me that it would likely be a rare occurrence, but I was reading about a crash involving it so was just wondering what the 'right' thing to do was... It sounds like the right thing to do is get an instrument rating :p

Two small points: climbing in IMC is probably a dangerous maneuver for a non-instrument rated pilot; and not all countries include instrument skills in basic training.

The 5 C's are specifically for lost aircraft.  Inadvertent IMC should be handled by either an immediate climb or descent back to VMC, or a level 180 degree turn, if you flew laterally into IMC.

I suppose the other advantage to the 180 is that even if it doesn't take you out of IMC, it should take you along the obstacle-less path you just flew down

@JonStory The 180-degree turn is also supposed to be one of the things you practice as part of the limited instrument training you get in US private pilot training. You should hopefully be able to make the 180-degree turn without screwing things up too badly and killing yourself, if you trust your instruments.

@voretaq7 Couldn't a quick 180 degree level turn be the wrong move though if you were, say, flying near some mountains?  Wouldn't gaining altitude while contacting ATC be your best bet?  Just trying to sort through this logically...

@JayCarr Sure, if you are instrument rated you can just climb to the MSA (which you should be at anyway?) and then file IFR and carry on your merry way.  However, if you are not instrument rated its a legitimate emergency and you need to immediately get back to VMC.  The trouble is, the only VMC you know about is the one you just left.  If you climb and then 180 you might climb into another layer of IMC you didn't realize was there earlier.  It is imperative that you make an immediate correction back to known VMC if you don't have an instrument rating.

@JayCarr Hopefully you're aware of any mountains in the vicinity and were maintaining a significant amount of separation from them anyway. The only way this would prevent a 180 that I can think of would be if you just flew through a narrow mountain pass.

A visual pilot flying into instrument conditions is a serious emergency. It's much better to avoid the situation in the first place which is why there's a significant amount of training around preventing that from happening , namely in learning meteorology and practicing good flight planning. Pilots should always be looking out for deteriorating conditions, and planning an escape route, or a precautionary landing, even if it's in a field.
The actual training pilots get for inadvertent flight into IMC is to do a 180 degree turn on instruments while maintaining a stable altitude, and then fly out of the cloud they've gotten into. This won't always work, it is possible to get into IMC gradually, especially at night or over the sea (It's happened to me but I have an instrument rating so no big deal), or have IMC conditions form over an area all at once. In these situations a 180 degree turn isn't going to get a pilot to safety so they should:

Don't panic, you will get through it
Fly the airplane: concentrate on maintaining controlled, level flight. The artificial horizon is your bestest friend in the whole wide world right now, but don't forget to check your other instruments and do your regular engine checks and carb heat
Get your aircraft set up for flight in cloud or bad visibility, so pitot heat on, navigation lights on
Call air traffic control if available, notify them of the situation and ask for assistance. ATC can help the pilot find an area with better visibility, or direct him/her to an airfield with instrument landing facilities. They can also get someone on to help talk the pilot through setting the instruments available for an instrument landing, or do a surveillance radar approach
Use navigation aids to keep aware of location and to keep clear of obstacles. ATC will probably direct you, but you still need to be aware of your location and situation. If there's no ATC it's all up to you, so fly yourself to the biggest airport around, or one with lots of space and as little terrain as possible. Climb if necessary to avoid the tallest obstacle around

To add to what you are saying about this situation being a serious emergency studies have been done on private pilots in IMC. A pilot with no IFR training in IMC conditions survives less than 3 minutes on average.

I didn't know that statistic @usernumber. That's pretty scary!

@GdD See the link in falstro's comment on the original question. It's definitely scary!

If that's true then the answer to the question is probably: die.

Likely a very valid answer, then. 3 minutes? Ouch

It's relatively easy to avoid IMC during the day over land, when you have a clear horizon it's easy to tell when it starts to disappear and take action. At night or over the sea it's much less straightforward, and you might not realize until you are at an unusual attitude when recovery on instruments is challenging even with training.

@usernumber That's a scary number; do you have a reference to some of those studies?

Question about the 180 turn: If you're in mountainous/rocky/unknown terrain, wouldn't you want to climb first? A wide turn in unknown terrain with no visibility seems to me like a good way to go CFIT.

The point of the 180 degree turn is to get a pilot back into visual conditions before he/she becomes disoriented. Climbing is more likely to get you deeper into cloud, and the deeper you get the more likely you are to lose control. Unless you have a very good idea of the surrounding terrain you are better off doing a 180 degree turn and relying on good fortune.

@JasonC, my aviation weather professor told us that number during the first lesson to get our attention, but I haven't found any link to an article that might confirm.

@JasonC This leaflet describes a 1990s study at University of Illinois which concluded that on average, from their sample of 20, it took 178 seconds for a VFR pilot to lose control in IMC. However, here's an article which debunks this story. In particular, all the gyro instruments were apparently covered during the experiment, and the University of Illinois no longer seems to have even the excerpt, let alone the entire story.

@TUMBLEWEED Do people without instrument ratings actually fly aircraft with 6 nm turn diameters? I'd think most of them would be in light aircraft that have turn diameters of a fraction of a mile. A jet would generally have a much larger turn radius than most light GA aircraft. Consider that the downwind->base->final correspond to a 1 statute mile turn diameter and we still roll out on base and fly straight for a while before turning final.

Special case: our university has an exceedingly good autopilot installed in all of our trainers.  If one of our private pilot students gets into IMC by mistake, they hit the button marked "Straight & Level" and then let Otto fly the 180 turn to exit IMC.
While not every student or private pilot has access to the level of cockpit automation that we do, even a wing leveler + elevator trim might be enough to keep you alive until you can get your bearings.
As an anecdote, my first time in IMC, I had over three hours of hood time, I had been fully briefed on what to expect and I knew that my body was going to lie to me.  Not more than thirty seconds in the cloud and I knew beyond a shadow of a doubt that the airplane was tumbling backwards.
If my instructor hadn't been there I would have pushed the nose into the dirt and held it there until I broke out of the cloud or hit the ground.

It's official - your body was trying to kill you.

As others have said, this situation is best avoided. There's a term for trying to sneak under the clouds: scud-running. It can be deadly. As the dew point drops, the cloud ceiling falls. Combine that with rising terrain and accidents can happen. The spread between the dew point and the air temperature is a critical tool (the higher the better) for avoiding low ceilings. This is why the dew point and air temperature are part of weather information.
It's really critical to understand how disorienting IMC can be. You have to resist the temptation to fly with your eyes out the windscreen and switch to flying using the instruments. The expression "flying by the seat of your pants" is used a lot and it's just not true. One of my instructors wanted me to experience how undependable this is. He had me close my eyes and attempt to fly straight and level. After about 20 seconds, he told me to open my eyes. I was banked left about 20 degrees in a nose down attitude. While I had my eyes closed, I was certain that I was rolling to the right and climbing. That was a sobering lesson.

Flying by the seat of your pants (literal, actually) only applies to coordination/avoiding sideslip. And it is actual seat of the pants, not feel of balance because that one is getting conflicting information.

I read a few times that the attitude indicator is your friend. That is not so much true. Just last night I was in IMC and my attitude indicator was acting up, a 2 month old AI... If you are flying anywhere near IMC conditions, you best be well rehearsed in flying by and trusting your life in that set of instruments(all of them), 3 hours a year ago in training is not enough. If you accidentally get stuck in IMC conditions and try to feel your way out of it, you'll be ascending into the heavens within minutes. I had never been in the soup, even as a passenger, until after I got my IR. I didn't realize the skill I had developed in instrument training until I took a non IR rated private pilot into the soup with me. Every 30 seconds he was asking why we were banking so hard when we were level, or why we weren't turning when we were. Thats coming from a guy just got his license and did his 3 hours in the past 2 months or so. Thats scary.
If you see IFR or degrading visibility anywhere near or around your flight, my advice is to stay on the ground

The airport I learned to fly at was the home of many planes.  On Friday afternoon / evening during the summer the people would fly their planes to the beach, a couple of hours east of the airport.
One Friday afternoon while I was learning I was practicing touch-and-go's.  I knew that my time was limited because there was a storm south of the airport, about an hour away.
For about thirty minutes I had the airport to myself, but then some of the earlier departures to the beach started returning.  Next thing you know the airport has a lot of planes in the pattern.  And of course I am last!  I never lost sight of the ground but the thunderstorm I was in scared me beyond believe.  (At one point I even considered landing at Andrews AFB that I could see and was in sunshine)  My instructor got on the radio and eventually talked me through it.
Several weeks later while doing my long cross country I got a weather report indicating a thunderstorm ahead of me.  Several minutes earlier I had passed over the airport at Orange, VA.  Half an hour after landing at Orange, VA the thunderstorm hit.
GA pilots that test mother nature are a fatality waiting to happen.

First of all, as a VFR pilot you are usually always watching weather and the chance that visibility just instantly drops is unlikely.  That being said, you do have some "hood time" when training for your private pilot rating that you will likely fall back on ... but more importantly, if you are flying a modern aircraft, is to rely on autopilot.  Turn the aircraft over to the autopilot, lookup weather conditions around you on your MFD (or call Flight Service and get their advise on where to go); then adjust the heading or punch direct to the destination with the better conditions.  I would also notify ATC of my condition and if things were really bad, declare an emergency.

Just flipping on the autopilot and continuing inside a cloud while trying to determine where to go is dangerous. The three hours in the PPL curriculum is for emergencies, and currency is essential when flying in IMC. VFR into IMC is a very dangerous situation, and grounds for an emergency (though keeping the plane upright should take precedence over calling ATC.)

A pilot must have a very good kinesthetic sense : his or her position in the air, in the space. When you have that natural quality; training helps but it is natural, it is much easier to have the same feeling for you plane. Early pilots did not have any kind of instrument and they crossed very long distances. Bleriot, the French pilot, went over he Channel in the 1920s. Some veteran pilots are more competent than now a days when some feel over confident in their electronic system. The pleasure of piloting is feeling safe and confident in its own abilities. Piloting is a vocation; you have to have natural predispositions for it. When you have them, you like the job. You are less stress. Kinesthesie is the senses of a human being measuring motion in space, so in the air too.

Welcome to Aviation Stack Exchange! Sadly, your answer is incorrect - as mentioned in other answers, there are physiological reasons why humans, no matter the skill, cannot remain in control of an airplane in IMC based solely on kinesthetics.

Sure, some folks have better kinesthetic sense. But in IMC flight an Olympic gymnast will succumb to the tricks the inner ear just as fast as anyone else.

Its not just "tricks" of an inner ear... you can literally enter inverted flight with 1G through your butt the entire time, so that you feel you are sitting normally, and never detect the shift.  It is acceleration and physics, not physiology.  This is why airplanes must have Gyros.

Early pilots had no instruments, true. They also frequently died because they were trapped in clouds or fog. There's a reason airmail pilots were instructed to bail out rather than try to land through fog.

@abelenky: Flying straight and level will be indistinguishable from flying along many other paths, but I would think the way in which the plane responds to controls would vary.  If the wings are level and one elevators up and down, the all changes in acceleration will remain symmetrical left to right; if the plane is banking, however, I would think the elevator action would cause non-symmetrical changes in acceleration.

@supercat logically, what you say makes sense - in reality that just isn't how it works, because you aren't attached to the ground and your body has no fixed plane of reference

@supercat In the frame of reference of the pilot, pulling the elevator back while banking will produce a very similar force vector to pulling the elevator back while the wings are level. Either way, the force vector will point up relative to the pilot (just not necessarily up relative to the surface of the Earth.)

@reirab: If the pilot isn't feeling any lateral G-forces while banking, that would suggest that the pilot is in a perfectly-coordinated turn (I think that's by definition).  Would a perfectly-coordinated turn remain perfectly coordinated while the elevator setting was changed but the rudder wasn't?  I thought keeping a turn coordinated required adjusting both.


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Why is the minimum runway length non-linear in relation to the landing weight?
The graph below shows the landing runway length requirements for a Boeing 747-8.

(taken from the Boeing 747-8 Airplane Characteristics for Airport Planning)
Considering the fact that the kinetic energy and impulse are directly proportional to the mass, I would have expected this graph to be linear – but clearly that's not the case. What is causing the non-linearity here?

Probably a function of the efficiency of the spoilers and brakes in dissipating the kinetic energy (${1\over 2}mv^2$ is non-linear with velocity itself).  Could also be affected by the safety margins built into that landing distance, as those numbers do not represent the absolute minimum distance needed to stop the airplane.

@casey Decreasing brake performance was my first idea too, but then I would have expected a more gradual change in slope.

Kinetic energy is proportional to mass, but so is the braking force! (it's really proportional to weight, but for all practical purposes those two are proportional to each other).

While the kinetic energy is proportional to mass, it is not proportional to velocity.
The heavier the aircraft is, the higher the landing speed. So the stopping distance increases mainly because of the higher landing speed.
Comparing two landings, first at mass = $m_1$, the second at mass = $m_2 =1.1 \cdot m_1$, the landing speed will be $\sqrt{\frac{m_2}{m_1}}$ higher during the second landing.
The kinetic energy during the landing will scale proportional to the square of the mass.

Ah, I didn't realize the landing speed was also affected by the mass, but obviously that has to be the case. Then the only remaining question is why the graph doesn't look like a parabola, but more like two straight lines spliced together.

@Ventero I'm not sure a parabola would be expected. The aerodynamic drag and reverse thrust are non-linear with speed, but unaffected by aircraft mass. The wheel braking system is probably capable of providing deceleration independent of the mass (more mass = proportionally more grip = proportionally higher braking force = same deceleration) up to a mass where the maximum breaking power (heat generation) is reached and the deceleration will need to be lower. This could be the explanation for the two segment, however some curving is still expected. Simplification is probably the explanation.

The stopping distance is not proportional to kinetic energy. Since friction is proportional to normal force (which is weight), the maximum deceleration the brakes can effect does not depend on mass at all. So the stopping distance should only depend on square of speed and since speed depends on square root of mass, one would still expect linear relationship. So this requires explaining what are the limiting factors for brakes.

authors: Виталий Гейнак


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Can a gyro-copter soar?
If one centers the gyro-copter in a thermal and then simulates a hover facing headwind; can the gyro-copter climb up like that ?
Is it technically possible or is it advisable....

An airplane isn't capable of hovering. Did u see the video ?
A glider needs to circle to soar...

A gyro-copter has much less wing area...

The gyrocopter in the video was hovering in 15kts winds. And gyrocopters don't stall....as far as I know..

I need to work out the math for this, but an issue complicating the question is that the L/D of the gyrocopter would change in the updraft.  So, like a helicopter in autorotation, a gyrocopter derives lift from flow passing upwards through the rotor as it flies forward on its propeller.  However, if the aircraft is in a vertical updraft, the freestream is no longer directed horizontally, but more vertically, increasing the angle of attack on the rotor blades and directing your vehicle's drag force in the upward direction (magnitude and direction, naturally, depends on your flight speed, thermal strength, etc.).
Now, gyrocopters have at cyclic and collective pitch control (generally speaking), so you could vary the collective in order to maintain a lower angle of attack, gain stall margin, and maintain altitude...or you could take advantage of the updraft on your rotor to gain altitude for "free"!  This also assumes that you have sufficient collective pitch travel to get your blades at a low enough angle of attack to stop producing upward-directed thrust.
You could try to pitch over too, thus redirecting the rotor thrust vector forward and spoiling a lot of the inflow, but this is starting to get into the downside of thermalling in helicopters: namely, that, if the updraft is sufficiently strong to stall your blades (no matter the pitch setting) but also strong enough that the vertical drag on the airframe can induce a climb...it's not going to be a good day.  I'm thinking primarily of updrafts that occur in the presence of thunderstorms--they have been known to be strong enough to suck aircraft up into the clouds.  Similarly, if you make your way out of the thermal, they are generally surrounded by regions of strong sink because of the recirculating air (http://www.drjack.info/INFO/DELMONTE/thermal.page.html), which not only is going to load the blades completely the opposite of how they were in the thermal (so your inertial loads spike, provided you don't have mast bumping problems...in which case you lose the aircraft right then), but, if the sink is strong enough, you might find yourself in vortex-ring-state or the like and lose control--if only temporarily.  At least from my brief experience in an S-300Cbi and R22, helicopters don't like to fly, so even brief periods of control loss would be bad.
So yeah, I think it's technically feasible, and, in some cases, very dangerous.  I wouldn't try to set an endurance record in a rotary winged aircraft doing this.

The rotor has no way to know which way the surrounding air is going. If you're in an updraft you'll add the updraft to your vertical rate of ascent.

True, the updraft will be be identically the inflow to the rotor (less the gyrocopter's horizontal velocity vector), but, if you model the updraft as a sharp-edged vertical gust, won't it result in a local change in angle of attack at the rotor?  That change will necessarily be "softened" by the aircraft vertical velocity (since the gust hits the fuselage first), but it seems odd to me that the aircraft would necessarily transition upward at the speed of the updraft.  Shouldn't any motion should be proportional to the aircraft's vertical drag area and the square of the updraft speed?

Any aircraft, from a helicopter to a 747, can soar.
All it has to do is enter and maintain its position in rising air. How the pilot accomplishes that would be based on picking a strategy for staying in the rising air, and using his skill to do it.

Well, provided that the air is not just raising, but raising faster than the aircraft needs to descend to maintain flight. I am not sure what kind of L/D gyrocopters have.

you don't have to shut off or null the engine to glide.

@rdp  A 747 can soar; in theory. I'm thinking about 'for all practical purposes'. Have you seed a gyrocopter soar or come across any such video?

you asked "technically possible or advisable". maybe you want to edit the question


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Is it technically feasible to dampen the control stick in an Autogyro?
The control stick in a gyrocopter is too wobbly for a glider pilot's liking. Is there a way to dampen the stick in a Gyrocopter [Eg. the Air command] to make it feel as smooth and light as one would in a Sailplane; without adding too much weight....

If we could get every aircraft to handle the same we'd be happy pilots... Unfortunately I think this is just something time-in-type will train out of you.

@RonBeyer I feel like it is technically feasible.Also, getting used to a wobbly stick would affect one's glider flying.


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Can training for an Instrument Rating be applied towards a commercial pilot certificate?
Per 14 CFR 61.129, a person who applies for a commercial pilot certificate for airplanes (both single and multiengine) must log at least ten hours of instrument training.
Assuming a pilot obtains their instrument rating prior to training for their commercial pilot certificate, can the instrument time logged during training for an instrument rating be used to satisfy this requirement (assuming class of aircraft requirements are met)?

Short answer: yes, if the training has been logged with the remark that it meets the requirements of both 61.129 and 61.65.
This topic became confusing because of an FAA interpretation that says:

[...] are the requirements of 14 C.F.R. §61.129(c)(3)(i)
  [commercial certificate] met by the student getting an instrument
  rating or training for an instrument rating? The answer is no. The
  training giving to satisfy the instrument training aeronautical
  experience of §61.129(c)(3)(i) may also be used to count towards the
  aeronautical experience of §61.65(e) [instrument rating], but the
  opposite is not true. The reason for this is that the training
  required under §61.65(e) is general, while the training under
  §61.129(c)(3)(i) lists very specific operations that must be
  accomplished to satisfy the requirements.

But that interpretation was surprising to many people because it implied that a commercial certificate requires additional instrument training, even if you already hold an instrument rating. So AOPA requested a clarification (more information here); you can read the whole thing, but the key statement from the FAA is this:

We are merely clarifying the requirement that the applicant for a
  commercial pilot certificate provide evidence that they have met the
  requirements of §61.129. There is not an exact equivalence between the
  training required for an instrument rating under §61.65 and the
  aeronautical experience requirements under §61.129.

Practically speaking (as the AOPA article explains) that means that your CFII should explicitly log the training as covering both requirements:

[AOPA] urges instrument pilot applicants and flight instructors to be sure
  that instrument training is clearly logged to indicate that the
  training given meets the requirements of 14 CFR 61.65 as well as those
  of 14 CFR 61.129. That would avoid questions about the training’s
  applicability should the pilot one day advance to training for a
  commercial pilot certificate.

Yes, your instrument training conducted during your IFR certificate will count towards a Commercial certificate.
This is based on the assumption that your flights have been logged by a current CFII.
There may be additional IFR related training that pertains to CPL such as meeting certain requirements as set out by the Practical Tests Standards booklet (PTS).

Airmen Certification Standards (ACS) is replacing PTS. IMO the primary change is the explicit addition of risk management.

Yes, and the acid test is what the examiner (DPE) considers acceptable. So as a CFI, what I do, if there is any doubt, is to create a summary of the requirements, and reference the date&time for the log entry, so that the DPE can establish that the requirements are satisfied.
CFI initial rides tend to get extreme scrutiny, and I use the same approach there, namely a checklist of the essential requirements for the rating, and the references to show where those requirements were satisfied. The FAA inspectors love it.  The DPEs love it.  It makes everyone's job easier, and saves hassles.
So as a student, instrument or commercial, I would assemble your list of the rating requirements, and reference the log entries supporting those requirements.  Then have your CFI signoff on your worksheet after he reviews your data. Present a copy to your DPE (yep, a copy for his records if he wishes).  It will help your checkride start on a good note.
After 37 years, I have never had a student sent home because they did not meet the rating experience requirements.

You absolutely can and just about to everyone applying for a commercial certificate does do that.  Aeronautical experience is immediately transferable to an certificate you are seeking, provided it meets the guidelines for aeronautical experience listed in the FAR 61.129 for the specific certificate.
Much of the experience you log early on can be immediately transferable to other certificates, even in other categories or classes of aircraft. For instance a person who holds a commercial certificate in an airplane single engine land could apply for a commercial certificate in a rotorcraft helicopter with as little as 50 hours total time in helos; the rest may be transferred from the applicants flight experience in other aircraft.

Yes.  However, the CFI must log the training as accomplishing the instrument time for the commercial certificate.
See the Theriault interpretation.

That's not what this legal interpretation says. In paragraph three, it says "the training given to satisfy the instrument training aeronautical experience of §61.129(c)(3)(i) [instrument training for commercial pilot] may also be used to count toward the aeronautical experience of §61.65(e) [instrument rating], but the opposite is not true."

No.  Under the 61.65 aeronautical experience requirements for a commercial certificate, there is no requirement that the trial or simulated instrument time be earmarked for a commercial certificate.


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Where did the terms QNE, QNH, and QFE come from?
In the aviation community (at least outside North America), the terms QNE, QNH, and QFE are used to describe standard pressure, local altimeter, and field elevation, respectively.
But what is the origin of the "Q" code names?

Morse - see this answer

See also http://en.wikipedia.org/wiki/Q_code

QNE, QNH, and QFE are Q Codes - the Q Codes are designed for telegraph (or radiotelegraph) use where information is transmitted in morse code and brevity is essential (e.g. "QNH KJFK 2992 INS" is much shorter to tap out in morse code than "JFK Altimeter 29.92 inches of mercury")
They are still used in verbal communication (radiotelephone), though much less frequently.
ICAO defines a list of standard Q codes for use in aviation (this site has a list).

Regarding the choice of Q as the prefix for these codes, this is to avoid confusion with station callsigns. The ITU currently will not assign prefixes beginning with Q to any country.
(There may be further historical reasons behind the choice of "Q", but I'm not aware of any.)

"Q" is not a common letter in many languages (the Germans used it as space when encrypting with enigma, which didn't have a space)

@ratchetfreak That probably plays into the decision to use it as well -- Q isn't the thinnest part of the English dictionary, but it's also certainly not a commonly-used letter here either.

One of my PPL textbooks briefly discussed the origins of QNH. Unfortunately I can't for the life of me find the correct passage, so I am unable to reference this properly. But from memory:
It dates back to the early days of navigation when the main communication method was morse code through the radiotelegraph.  The aircraft, wanting the atmospheric  pressure for altimiter calibration, would basically ask the ground station "I have a question - what is the atmospheric pressure at normal height?" The 'normal height' reference over time became the sea level reference that we use today.
So, because this question was so frequently required - and therefore an awful lot to communicate through morse code - it was abbreviated. "I have a question" became Q, "what is the pressure at normal height?" became NH - the message transmitted therefore was simply QNH.
I presume the other Q codes evolved in a similar manner.

That sounds a lot like a back-formation, to me.  (I.e., "We have this pre-existing code, QNH. Can anyone think of anything it could stand for, so it's easier for people to remember?")

Q-codes can be questions or statements. Certain Q codes only make sense as one or the other, not both, whereas many can be used as both statements ("QTH SPRINGFIELD" meaning "my location is Springfield") and questions ("QTH?" meaning "what is your location?"). Also consider for example "QSL" meaning "I confirm receipt of your transmission" whereas "QSL?" means "please confirm receipt of my transmission". (With reservation for the exact literal meaning.)

I agree with David Richerby.  Without having a reference for this Q-code origin, I believe this statement is a back formation.  I will look forward to being proved wrong, however....

This may not be historically accurate (the Wikipedia page on Q codes has a statement to that effect), but it is a very useful mnemonic - QNH - Query Normal Height.


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What is the significance of hover performance in helicopters (HIGE, HOGE)?
I was looking at a helicopter performance chart and it listed two values in feet, identified as "Hover in ground effect (HIGE)" and "Hover outside of ground effect (HOGE)."
What do these numbers mean, and why are they significant?

Related: Should helicopters fly when they the lack power for vertical climb out of ground effect?

@fooot Great information on that link, thanks!

Ground effect is a condition where the performance of the aircraft increases while operating near a firm surface. In general, a helicopter is considered to be in ground effect when it is hovering less than one-half of its rotor diameter from the ground and the effects become negligible when the helicopter is more than a rotor diameter above the ground.
While hovering near the ground, the induced velocity at the rotor is reduced, which reduces the power requirement for a given rotor thrust (lift); equivalently, the rotor thrust is increased for given power due to ground proximity. Also, near ground, the rotor tip vortex is reduced.
Due to this, the helicopter can hover at higher gross weight (equivalently, at higher altitude for given weight) in ground effect (HIGE) compared to out of ground effect (HOGE).

Image from copters.com
Usually, the altitude at which a helicopter can hover at a given weight (and atmospheric conditions) is given for both HIGE and HOGE conditions. HOGE is much more restrictive compared to the HIGE. For example, the following image compares the hoer performance of R44 helicopter in and out of ground effect.

Data from helicopterforum.verticalreference.com and aneclecticmind.com
In a sense, HOGE represents the absolute limit of the helicopter performance and it should be considered for operational calculations where there is no availability of rigid surfaces for vertical takeoff and landing or their presence is not confirmed.


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Are there pictures of unassembled planes being transported around?
My google-fu is failing me here.
A friend was telling me about the assembly of carbon-fibre planes, and how the huge parts of these need to be transported long distances between countries.
Are there any photos of this?

Something like this? It's the Airbus Beluga which is used by Airbus to move parts of planes around Europe.

Or something like this, a ground transport of the A380 which doesn't fit into the Beluga?

For Boeing pictures, like this? It has nothing do to with carbon fiber, and everything to do with aircraft manufacturers having plants spread out over a bunch of places.

The answer is yes, as in the links posted, since photos at least exist for PR purposes. But I think this would be a better question if it were asking something different, maybe for some details about the transportation that would help get your google-fu started, and answers could include pictures like those posted to satisfy the current question.

@fooot yeah I agree that it's a marginal question. The original question was 'how are carbon fibre planes made?'

I'm gonna vote to put this on hold for now, because it's inviting answers of "here's these couple of pictures" and there's no definitive answer to the question.

Here you have pictures of wing upper cover being handled and transported:

(Image Source: www.airbus.com)
Wing upper cover is biggest single composite component on A350XWB.
Additionaly try google: "wing upper cover A350", "wing lower cover A350". Those are the biggest. And you can see them in various stages in google.

Google: A380 Transport fluvial